Inovio Biomedical Universal Influenza Vaccines Demonstrate 100% Protection Against Current Pandemic A/H1N1 Influenza Viruses In Animal Studies

Main Category: Swine Flu
Also Included In: Flu / Cold / SARS;  Public Health;  Immune System / Vaccines
Article Date: 31 Jul 2009 - 0:00 PDT

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Inovio Biomedical Corporation (NYSE Amex: INO), a leader in DNA vaccine design, development and delivery, announced that the company's SynCon™ H1N1 influenza DNA vaccines achieved protection against current circulating swine origin influenza A/H1N1 viruses in animal studies.

The company had previously reported interim data from an ongoing study in a pig model in which the SynCon™ based H1N1 vaccines achieved hemagglutination inhibition (HI) titers above the protection threshold in 100% of the vaccinated animals against the swine influenza virus (A/Iowa/35233/1999). In a continuation of this study, Inovio investigators tested the immune sera for responses against a virus isolated from the current circulating strain of swine origin influenza A/H1N1 (Swine A/Mexico/InDRE4487/2009). All the animals immunized with the SynCon™ H1N1 vaccine developed HI titers exceeding the 1:40 level commonly associated with protective immunity.

In a second study, the investigators immunized mice with the NP and m2E components of the vaccine and challenged these animals with a second related strain also isolated from the current circulating influenza A/H1N1 (A/Canada/AB/RV1532/2009). While all mice showed effects of virus challenge as judged by significant weight loss, the vaccinated mice recovered from virus infection-induced morbidity significantly faster compared to the non-immunized control animals.

In a previous study, the Inovio team demonstrated that mice immunized with Inovio's SynCon™ H1N1 DNA vaccine provided 100% protection in a lethal challenge study against an unmatched H1N1 virus that caused the 1918 Spanish flu, which killed over 40 million people worldwide.

The challenge of current seasonal influenza vaccines is they are not effective against new strains that emerge, like the present swine origin influenza A/H1N1. The CDC reported low human prevaccination response rates and cross-reactivity to swine origin influenza (A/California/04/2009), suggesting that current H1N1 seasonal flu vaccines were likely to be ineffective against the new 2009 A/H1N1 strains. Similarly, the USDA recently reported there was limited cross-reactivity against the new 2009 A/H1N1 virus in pig herds vaccinated with existing swine influenza vaccines.

Dr. J. Joseph Kim, Inovio's CEO, said, "The latest data further underscores the potential of the SynCon™ technology to create vaccines capable of protecting against emerging pandemic influenza viruses. Our SynCon™ influenza vaccines were developed prior to the emergence of the current swine flu strains and have yielded strong protective responses in animal models against a variety of unmatched influenza strains. This is an advantage for our universal flu program over conventional influenza vaccines, which are strain-specific. Inovio, along with its collaborators, is amongst the first groups to report on the successful protection of vaccinated animals against a virus challenge with the 2009 influenza A/H1N1 virus. We are also one of the first groups to report on preclinical results regarding this virus using a large-animal model like pigs, a more natural host for the current influenza pandemic."

Inovio's novel SynCon™ technology enables the company to design DNA-based vaccines with the potential to protect against unmatched sub-types and strains of pathogens and provides the opportunity to have vaccines on hand against new strains that perpetually emerge, as in the case of influenza. Inovio has created SynCon™ DNA vaccines based on influenza HA, NA, and NP proteins from strains H1N1, H2N2, H3N2, and H5N1, which make up the majority of seasonal and pandemic influenza. Resulting vaccines could target seasonal as well as pandemic-potential influenza strains such as avian influenza and swine-origin flu, which has already been designated pandemic status. Significantly, being based on a common set of antigens derived from a broad range of flu strains, a universal vaccine would have the potential to provide greater protection against new, unmatched flu strains.

Source
Inovio Biomedical Corporation

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